TEXTILES.ORG
By Felon Wilson
Some say as much as 50% of the nation’s potable water is used for non-potable applications such as irrigation. A long discussed and growing trend is water reuse, simply defined as a beneficial use of reclaimed water. One state defines reclaimed water as “domestic or municipal wastewater that has been treated to a quality suitable for beneficial use.” Water reuse has reached a level of national importance that in 2020, EPA released the National Water Reuse Action Plan (WRAP) to promote and advance water reuse through collaboration with several national organizations including the Water Environmental Federation (WEF).
Why use reclaimed water?
The water is less expensive to use or to treat and users benefit from the savings.
The end use is typically located close to the source, minimizing distribution costs.
It is a drought-proof source of water.
It is the only source of water that automatically increases with increased economic activity and population growth.
It helps conserve traditional sources of water such as groundwater and surface water.
What are the challenges or roadblocks to using reclaimed water?
Many water reuse applications can be seasonal which is disruptive to the treatment process. Geomembrane-lined storage basins are typically used for extended effluent storage.
Treating wastewater for reuse requires an advanced process which can result in higher costs.
Public acceptance of what many consider to be unclean water is often a challenge.
The reclaimed water must be stored and distributed completely separately from treated water used for other things, including potable purposes. Pipes, pumps etc. handling reclaimed water are mandated to be purple.
Special permitting is required.
Reclaimed water originates at a Water Reclamation Facility (WRF) where reaching a desired level of purity involves a standard secondary treatment process followed by full advanced treatment which may include ultrafiltration and reverse osmosis, then followed by disinfection. A WRF is a separate facility than a potable water treatment plant. All equipment, piping, etc. is in no way connected to any potable water treatment, storage, or distribution. Various regulations, usually on a state level, dictate the necessary quality of the water based on the end application for the reclaimed water. The reclaimed water can be treated to a level as pure as potable water as demonstrated by Hillsborough County Public Utilities (Florida) first providing ultra-pure reclaimed water to local brewers who then highlighted the finished product at WEFTEC 2016.
As mentioned above, managing storage of reclaimed water is a necessity because while the inflow of reclaimed water is regular, the use of the water is not, or may not be. That is somewhat due to the specific end uses which are regulatory driven. Some permitting agencies are specific about the amount of storage required while some are determined by the utility agency and/or their consulting engineers. Regardless, proper, and adequate storage of reclaimed water is a necessity for a water reuse initiative.
In the next post, two water reuse projects successfully using geomembrane-lined storage impoundments will be discussed.
For more information about impoundment linings, visit XR Geomembranes here.